Electrical  musical string instrument



June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet1 INVENTOR.

OCTAVIO JOSE ALVAREZ AT TORNEY June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet2 1 I I I I], I I!!! It I I///// 1 1/ 11 1111/1 1 111) zrv INVENTOROCTAVIO JOSE ALVAREZ ATTORNEY June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet3 INVENTOR.

OCTAVIO JOSE ALVAREZ ATTORNEY June 30, 1964 o. J. ALVAREZ ELECTRICALMUSICAL STAR ING INSTRUMENT #8 Sheets-#Sheet 4 Filed June 25, 1958 FIG./5

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INVENTOR.

OCTAVIO JOSE ALVAREZ fiu' fim J J/W ATTORNEY June 30, 1964 0. J. ALVAREZ3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet5 eels/5,64

INVENTOR.

OCTAVI O JOSE ALVAREZ BY .5 JAM? ATTORNEY June 30, 1964 o. J. ALVAREZ3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet6 INVENTOR. OCTAVIO JOSE ALVAREZ ATTORNEY June 30, 1964 o. J. ALVAREZ3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet7 64 FIG. 22

INVENTOR.

OCTAVIO JOSE ALVAREZ BY m .r- 14.x

ATTORNEY June 30, 1964 o. J. ALVAREZ 3,139,476

ELECTRICAL MUSICAL STRING INSTRUMENT Filed June 25, 1958 8 Sheets-Sheet8 FIG. 23

sCllldl'ole a: FIG. 25

INVENTOR.

2 OCTAVIO JOSE ALVAREZ AM J. f/n/u/ ATTORNEY United States Patent3,139,476 ELECTRICAL MUSICAL STRING INSTRUMENT Octavio Jose Aivarez, 6E. 65th St, New York, N.Y. Filed June 25, 1958, Ser. No. 744,559 33Claims. (Cl. 84-413) The present invention relates to musicalinstruments.

More particularly, the present invention relates to musical instrumentssuch as pianos which are electrically operated so as to produce musicalsounds which simulate and are the same as the sounds of a conventionalpiano.

Electrical pianos are relatively expensive and complex. Furthermore, theelectrical signals which are amplified are not always pure andundistorted. For example, as a result of the damping of vibratileelements of such a musical instrument hissing sounds are created whichare difficult to eliminate. Also, in the damping of the vibratileelements the latter are placed in a position other than that which theywould naturally assume if unstressed, and as a result the vibratileelements require periodic adjustment in order to maintain the musicalinstrument properly tuned. it should be noted that the sameconsideration applies to the strings of a conventional piano. Also,where vibratory motion of a vibratile element is relied upon forinitiating the creation of a musical sound, it is diflicult to supportthe vibratile element in such a way that its support is completelyinsulated from and does not participate in any way in the creation ofthe musical sound. Some supports superimpose their own vibrations on thevibrations of the vibratile elements, and furthermore many supports forthe vibratile elements do not remain dimensionally stable over alongperiod of time with the result that the changes in the shape and size ofthe supports for the vibratile elements also produce distortions whichnecessitate readjustments. Such lack of dimensional stability of thesupports for the vibratile elements occurs particularly where suchvibratile elements are set into vibratory motion as a result of inertiaforces transmitted to the vibratile elements through their supports.

One of the objects of the present invention is to provide a musicalinstrument of the above type which is of a relatively simple,inexpensive construction and which at the same time is quite compact andcapable of operating reliably over a long period of time with a minimumof maintenance.

A further object of the present invention is to provide a musicalinstrument of the above type which will require no re-tuning.

Another object of the present invention is to provide for a musicalinstrument of the above type a unit which includes a vibratile elementof the musical instrument and which can be purchased as a unit toreplace a vibratile element in the instrument.

An additional object of the present invention is to provide a structurewhich supports the vibratile elements of the musical instrument in sucha way that the supports themselves do not in any way participate in theproduction of the musical sound even when the vibratile elements arevibrated as a result of transmitting inertia forces thereto throughtheir supports.

It is also an object of the present invention to damp the vibrations ofthe vibratile elements without producing any hissing sounds or otherundesirable sounds.

Still another object of the present invention is to provide in a musicalinstrument strings which are not sensitive to corrosion in certainclimates.

It is furthermore an object of the present invention to provide amusical instrument which is capable of behaving in every way in the sameway as a conventional musical instrument and which even eliminates someof the faults ofa conventional musical instrument.

Furthermore, the objects of the present invention include the provisionof a musical instrument such as a piano which is capable of havingpedals thereof operated for the purpose of sustaining a musical tone.

It is also an object of the present invention to provide a musicalinstrument of the above type which is capable of interrupting themusical tones and reliably preventing the continuation thereof and isalso capable of repeating the same musical tone rapidly with distinctextremely short periods of silence between the repetitions of the sametone.

Among the objects of the present invention is also the provision of amusical instrument which is capable of operating reliably with all typesof vibratile elements Whether the latter are extremely fine and delicateor whether they are relatively heavy and in the form of metal bands orspirals.

With the above objects in view, the present invention includes a musicalinstrument whereinan elongated vibratile element and a support meanstherefor form together at least part of a unit which can be connected toor removed from the musical instrument. This vibratile elementparticipates in the production of the musical sound when it is set intovibratory motion, and it is charged either electrically or magneticallyand cooperates with other elements such as pick-up coils or condenserplates, or the like, to electrically produce the musical tones. Thevibratile element is set into vibratory motion by the transmission ofinertia forces thereto, and in accordance with the present inventionthese vibratory motions of the vibratile elements are damped bothmechanically and electrically, and means are provided for preventingthis damping when desired in order to sustain a musical tone.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIGURE 1 is a longitudinal axial sectional elevational view of a unitaccording to the present invention, this unit including the vibratilemember as well as the support therefor and a mechanical damping means;

FIGURE 2 is an axial sectional elevational view of another embodiment ofa unit according to the present invention which includes the vibratileelement, a mechanical damping element, and the support for the vibratileelement and mechanical damping elements;

FIGURE 3 illustrates the manner in which the damping elements of FIG. 2are magnetically actuated;

FIGURE 4 shows a stage in the process of manufacture of the structureshown in FIG. 2;

FIGURE 5 illustrates another stage in the process of manufacture of theunit of FIG. 2;

FIGURE 6 is a perspective view of one of the damping elements of thepresent invention, this damping element having a structure differentfrom those shown in FIGS. 2-5;

FIGURE 7 shows a unit similar to that of FIG. 2 but including dampingelements as illustrated in FIG. 6;

FIGURE 8 illustrates an intermediate stage in the operation of thedamping elements of FIG. 7;

FIGURE 9 shows the elements of FIG. 8 when they have progressed furtherand are located in their final damping position;

FIGURE 10 is a longitudinal sectional elevational view of anotherembodiment of a unit according to the present invention;

FIGURE 11 is a longitudinal sectional elevational view of still anotherembodiment of a unit according to the present invention which includes avibratile element, damp- Patented June 30, 1964 ing means therefor, anda support for the damping means and vibratile element;

FIGURE 12 shows the structure of FIG. 11 with the vibratile elementdamped so that it can no longer vibrate; FIGURE 13 is a transversesectional view illustrating details of the damping structure of FIGS. 11and 12;

FIGURE 14 is a perspective view of one of the damping elements of FIGS.11 and 12;

FIGURE 15 illustrates in a partly diagrammatic manner part of the entireassembly associated with a key of a piano :and including one of theunits of the present invention;

FIGURE 16 shows the structure of FIG. 15 and the position it takes whenthe key has been moved by the operator to the operating position;

. FIGURE 17 illustrates the position which the parts of FIG. 15 takeswhen the operator actuates a pedal of the piano;

FIGURE 18 is a partly diagrammatic illustration of another embodiment ofa piano structure according to the present invention;

FIGURE 19 is a diagrammatic illustration of' still another embodiment ofa structure according to the present invention, the parts being shown inFIG. 19 in the position they take when the piano key is at rest;

FIGURE 20 shows an embodiment slightly different from that of FIG. 19,the structure being shown in FIG. 20. in theposition it takes when thepiano key has been moved to its operating position;

FIGURE 21 also shows an embodiment of the invention somewhat differentfrom that of FIG. 19, FIG. 21 showing the position the parts take whenthe pedal is actuated;

FIGURE 22 is a partly diagrammatic illustration of a still furtherembodiment of the present invention;

FIGURE 23 is a partly diagrammatic illustration of still anotherembodiment of a piano according to the present invention, the partsbeing shown in FIG. 23 in the position they take when the piano key hasbeen moved to its operating position;

FIGURE 24 shows the embodiment of FIG. 23 with the piano key in the restposition thereof; and

FIGURE'ZS shows the structure of FIGS. 23 and 24 with the key of thepiano in its rest position and after the pedal has been actuated.

Referring now to FIGURE 1 of the drawings, there is illustrated thereina unit according to the present invention, this unit including thevibratile element 31 as well as the'support therefor and a damping means44, 45. As may be seen from FIG. 1, an elongated hollow glass tube formsa housing for the vibratile element 31 which may be in the form of anelongated wire having heads 32 and 33 located at its opposite ends. Thetube 30 is closed at its leftend, as viewed in FIG. 1, and the vibratileelement 31 extends through an opening at the end wall of the tube 30with the head end 32 thereof engaging the exterior surface of this endwall to limit the movement of the vibratile element to the right, asviewed in FIG. 1. A plate'34 of an electrically non-conductive materialis located next to the open end of the tube 30, as illustrated in FIG.1, and this plate as well as the right end of the tube 30, as viewed inFIG. 1, are received ber 35 is formed with a threaded bore 37 whichthreadedly receives an elongated screw member 38 having at its rightend, as viewed in FIG. 1, a transverse notch 39 adapted to receive thetip of a screwdriver, for example, so'that the screw member 38 may beturned to adjust its 7 position. This screw member 38- is formed with anelongated bore 40 extending parallel to its axis, and the vibratileelement 31 extends through this bore 4t) and has its head end 33engaging the right end face of the screw member 38, as viewed in FIG. 1.apparent that the vibratile element 31 is deflected at the opening 36 ofthe plate 34 into the bore 4t) of the screw member 38, and turning ofthe screw member 38 will adjust the tension of the wire 31 between theleft end wall of the tube 30, as viewed in FIG. 1, and the left edge ofthe opening 36, as viewed in FIG. 1, which is tapered in the mannerillustrated in FIG. 1, so that the vibratile element 31 will besupported for free vibratory motion at its portion which extends fromthe left end of the tube 3% up to the plate 34. The screw member 38 maybe in the form'of a permanent magnet having the polarity illustrated inFIG. 1, so that the vibratile element 31 may be permanently charged inorder to participate properly in the production of a musical sound, aswill be apparent from the description below in connection with FIG. 10.

Once the tension of the vibratile element 31 has been properly set, asealing compound 41 may be placed at the front end of the cap member 35around the screw the tube 30, so that the interior of the tube 39 issealed 7 off from the outer atmosphere, and before the sealing compound41 and 42 is applied the interior of the tube 30 may be evacuated in anyknown way. is of particular significance where the vibratile element 31,has a relatively large mass, because in this way the air resistance tothe vibratory motion of such a vibratile element is greatly reduced.Furthermore, where a vibratile element 31 is of a relatively delicatenature it is completely protected by the above-describedsupportingstructure therefor. It should be noted that the vibratileelement 31 is shown in FIG. 1 in the form of a simple wire only by Wayof example.

The above-described unit of FIG. 1 further includes;

'45 are inserted into the tube 30 with the string 31' passing throughthe bore 46 before the plate 34 and the other elements are joined to theassembly. The ring 43 presses with its exterior surface against theinner surface of the tube 30 so that the ring 43 remains reliably at theleft.

end of the tube 30, as viewed in FIG. 1. 1

The use of an elongated tube such as the tube 30 supporting and housingthe vibratile element is of particular advantage not only with respectto the. protection of the vibratile element and the possibility oflocating the latter in an evacuated atmosphere, but also with respect tothe dimensional stability of the support. Thus, a structure such as theelongated tube 30 with its circular well will reliablymaintain itsconfiguration without being infiuenced in any way by interia forceswhich are transmitted through the tube 30 to the vibratile element 31,so that the tube 30 will never superimpose its own vibration on those ofthe vibratile element and will never change its shape or size so as toprovide distortions which cannot be controlled.

In the embodiment of FIG. 1, as well as in the other embodiments ofstring-carrying units of the invention described below, it is preferredto enclose the spring in a tubular housing made of glass for severalreasons. Thus, this material is not too heavy or expensive, need not beprecision machined, and at the same time is strong enough to maintainthe tuning stable. Also, glass is not too sensitive with respect tothermal expansion and is unlikely to become permanently distorted.Furthermore,

the current-conductivity of glass is too low to produce any.

Thus, it is Such evacuation p which would cause the string support tovibrate in interference with the string itself, and the result would beundesirable sound distortions and exaggerations.

The air-tight enclosing of the string protects it from corrosion andfrom dust and other particles which might greatly disturb the properoperation of the musical instrument. Also, an enclosed string can behandled without exercising great care during packing, shipping andmounting. Furthermore, by locating the mechanical damping elementswithin the tubular enclosure injury to the mechanical damping elementsis avoided.

The above described unit of FIG. 1 is manufactured separately and isalso sold separately, so that a purchaser can at any time replace a unitof his piano with a new unit as shown in FIG. 1, and the vibratileelement of the unit is already tensioned so as to have the propervibratory motion. In this way if for any reason it is desired to replaceone of the vibratile elements of a piano, then with the structure of thepresent invention it is only necessary to purchase another unit as shownin FIG. 1.

Of course, with the embodiment of the FIG. 1, if it should becomenecessary to retune the vibratile element 31, it is possible to turn thescrew 38 for this purpose so that purchase of another unit may not benecessary. Also, the forms which the vibratile element 31 may take arenot limited to those mentioned above.

FIG. 2 of the drawing shows another embodiment of the invention whichincludes an elongated tubular housing member 50 having at its right end,as viewed in FIG. 2, the end wall 51 to which the right end of avibratile element 52 is fixedly connected, in the manner shown in FIG.2. In the interior of the tubular housing 50 is located an elongatedplug 53, aid this plug as well as the tube 50 may be made of glass, forexample. The left end of the vibratile element 52 is connected to theright end of the plug 53, as shown in FIG. 2, and at their left ends thetube 50 and the plug 53 are fused to each other. Between the plug 53 andthe tube 50 are located a pair of elongated springy strips 54 and 55made of a magnetic material and carrying at their right free ends, whichare in the interior of the tube 50, pads 56 and 57, respectively, whichmay be made of rubber, cotton, or the like. It will be noted that thestrips 54 and 55 have their left free end portions, as viewed in FIG. 2,extending to the exterior of the unit beyond the left ends of the tube50 and the plug 53, as viewed in FIG. 2.

FIGURE 3 illustrates the manner in which the strips 54 and 55 areoperated in order to damp the vibratory motion of the vibratile element52. As is shown in FIG. 3 a permanent magnet 58 is placed adjacent tothe left free end portions of the strips 54 and 55, as viewed in FIG. 3,and in this way the strip 54 is given a North polarity while the strip55 is given a South polarity. As a result the ends of these strips whichare in the interior of the tube 50 and which carry the pads 56 and 57,respectively, are attracted to each other and engage the vibratileelement 52 at opposite faces thereof, respectively, and with equal andopposite forces, so that in this way any vibratory motion of thevibratile element 52 is damped, and at the same time because equal andopposite forces are applied toopposite face portions of the vibratoryelement the latter is in no way distorted by the damping means so thatit will not become stretched by the damping means and will not requirethe retuning. Of course, as soon as the permanent magnet 58 and the leftfree and portions of the strips 54 and 55 are spaced from each other sothat the strips 54 and 55 are no longer under the influence of thepermanent magnet, these strips will by their own resiliency return tothe position shown in FIG. 2 so as to release the vibratile element 52for vibratory motion.

FIGS. 4 and 5 show stages in the process of manufacture of the structureof FIGS. 2 and 3. As may be seen from FIG. 4 the plug 53 is firstconnected with the string 52 which is guided through an opening in theend wall 51 of the tube 50, and the strips 54 and 55 are locatedalongside of the plug 53 in the manner shown in FIG. 4. Then the plug 53with the strips 54 and 55 located against opposed surface portionsthereof are slipped into the tube Stl and the entire assembly is thenplaced on the frame 60 which is shown in FIG. 5. Thus, before the plug53 is inserted into the tube 59 this plug 53 is slipped through theopening of the left wall 61 of the frame 69, as viewed in FIG. 5, andthe strips 54 and 55 are also positioned so as to pass through thisopening. After the plug 53 has been located approximately at its properposition within the tube 50, the string 52 is pulled tight and formedinto an enlarged head end which engages the exterior surface of the wall51, as shown in FIG. 5. This may be done in any suitable way, as by heating the wire 52 to sever the portion of the wire which is located beyondthe end Wall 51 and so as to form the enlarged head end. Then the endwall 51 is placed in a T-slot of a member 66 which is guided formovement to the right and left by the member 67 carried by the rightwall 62 of the frame 60, and this member 66 is connected with a member65 which turnably supports the left end 64 of a threaded crank 63 whichpasses through a threaded opening in the right wall 62 of the frame 60.With this construction it is possible to turn the crank 63 so as toadvance the tube 56 to the right, as viewed in FIG. 5, with respect tothe plug 53 and thus tension the vibratile element 52 to a desireddegree. The condition of the vibratile element 52 is tested by the unit68 which includes a pick-up coil 68a, amplifier assembly 68b and loudspeaker 680, and which indicates the sound which will be produced byvibration of the vibratile element 52, and the structure for picking upthe vibrations and reproducing these vibrations into an audible sound isdescribed in greater detail below. When the desired tension of thevibratile element 52 is reached, which is indicated by the production ofthe desired sound, then with a burner 69, for example, the left end ofthe tube 50 is fused with the plug 53, and the portion of the latterwhich extends to the left beyond the tube 50 is cut-ofi leaving the freeend portions of the strip 54 and 55 which are located to the left beyondthe tube 56, and these free end portions are also cut off so as to havethe length shown in FIGS. 2 and 3.

In this way the structure of the invention may be very easily made, andif desired the tube 50 may be evacuated before the tube 50 is fused withplug 53. Of course, it is to be understood that the extending of thestrips 54 and 55 to the left beyond the tube 54 as shown in FIGS. 2 and3, is illustrated only by way of example. This feature is not at allessential, and the left ends of the strips 54 and 55 could also belocated within the tube 5% fused between the latter and the plug 53 orsimply gripped in the space between the tube 50 and the plug 53, sincethe magnetic force will act equally well on these ends even if they areembedded in the glass or other material of the tube 50 and the plug 53.

FIGURE 6 shows in a perspective view a single damping strip 70 similarto the strips 44 and 45 of FIG. 1, this strip 76 being bent upon itselfso as to have a pair of elongated substantially parallel portions one ofwhich has the padding 71 connected to its free ends, this padding beingof rubber, cotton or the like, as was mentioned above. The strip 70 ismade of a springy magnetic metal, such as any ferrous material.

FIGURE 7 shows a unit similar to that of FIGS. 2 and 3 including thedamping strips 70 which are mounted in the unit in the same way as thestrips 54 and 55 of FIGS. 2 and 3. Thus, FIG. 7 shows .the elongatedtube 72 having its end wall '73 connected with one end of the vibratileelement 74 whose opposite end is connected with the plug 75 which isfused at its left end to the left end of the tube72 with the dampingstrips 70 fixed between the plug 75 and the tube 72 and extending to theleft beyond the plug and tube, in the particular example shown in FIG.7.

perior to that of FIGS. 2 and 3.

FIGURES 8' and 9 show the operation of the damping strip 70.Referring'first to FIG. 8, it will be seen that when the permanentmagnet 76 is located close to the exterior ends of the damping strips7%, then these strips are respectively energized with the, differentpolarities as indicated in FIG. 8. Thus, the adjacent right free ends ofthe upper strip 70 of FIG. 8 both have a North polarity while theadjacent right free ends of the lower strip 70 both have a Southpolarity, in the particular example individual strips are now attractedto each other because of their opposite polarity and thus push againstopposed faces of the vibratory element so as to damp the vibrationsthereof without in any way stretching the vibratile element so that itwill not be lengthened and will not require tuning after a periodoftime, as was mentioned above.

This construction which is shown in FIGS. 7-9, is su- In the latterfigures, the forces with which the damping members engage each otherdepends upon the strength of the magnet. However, with the arrangementof FIGS. 79 when the damping members '76 have the position shown in FIG.7 their free ends will repel each other with a considerable force evenif the magnet 76 is relatively weak because the free ends of each strip70 are located closely adjacent to each other. Then when the padded endsare located close enough to each other to attract each other, verylittle of the magnetic force is delivered to the free ends of the strip70 which remain next to the inner surface of the tube 72. Almost all ofthe magnetic force goes through the padded ends of the strips, becausethis is the line of least resistance, and it is therefore possible withthe arrangement of-FIGS. 7-9 to provide the desired mechanical dampingwith a relatively weak magnet and in a very reliable, quick manner. Thespeed of the action is obtained by the initial repulsion forces in eachof the damping strips, as indicated in FIG. 8.

, FIGURE 10 of the drawings illustrates an embodiment of a unit of thepresent invention which is particularly suited for producing the lowertones of a piano. This unit includes an envelope 77 which is similar toconventional vacuum tubes and which is evacuated in a known way, andwithin this tube 77 is located the vibratile element 78 which in theillustrated example is coiled, and the convolutions of the vibratileelement 78 may take I any desired configuration and need not beabsolutely circular. This vibratile element 78 has a considerable mass,and the evacuation of the tube 77 reduces the air V cludes the springydamping arms 83 which are also made of a magnetic material and which areprovided with padding at their right ends, as viewed in FIG. 10, and

'the left ends of these arms are embedded in a member 82 which is fixedin the interior of the tube 77 and which ismade of anon-magneticmaterial such as a suitable plastic, for example. The member 79 extendsthreadedly through the plate 82 to the exterior of the tube so that thismember 79 may be turned to adjust the tension of the vibratile element78. An electrically conductive member 81 extends into the interior ofthe tube 77, and is coiled about both ofthe damping arms 83, and thenextends back to the exterior of the tube where the member '81 terminatesin a pair of contacts adapted to be engaged by another pair of contactsfor completing a circuit through the member 81, and as a result of thewinding of the member 81011 the arms 83 the latter are given apredetermined polarity which is opposed to the polarity. of thevibratile element '78, so that the arms 83 both move into engagementwith the vibratile element 78 to damp the Vibrations thereof when thecoil 80 and the element 81 are both energized. Because of the greatermass of the vibratile element 78 With respect to the arms 83, in

the embodiment of FIG. 10, the attraction force between the vibratileelement 78 and the members 83 is relatively great and with thisparticular embodiment the illustrated arrangement operates to reliablyprovide desired me-- chanical damping of the Vibratile element '78. .Themember 82 may be made of a resilient material, if desired.

It should be noted that the embodiment of FIG. 1 is similar in itsoperation to that of FIG. 10, in that the vibratile element 31 of FIG. 1is permanently charged with a North polarity by the permanent magnet 38.Thus, a pair of permanent magnets, for example, are applied with theirSouth poles to the mechanical damping elements 4% and 45 to give thelatter identical polarity. The

ends of each of the mechanical damping elements will repel each otherand the repelled ends of elements i4 and 45 are then attracted to thevibratile element 31 to press against opposed faces thereof with equaland opv posite forces so as to mechanically damp the same. Of

course, the mass of element 31 is sufiicient to prevent elemerits 44 and45 from repelling each other when they engage the element 31. FIGS. 15and 16 show how a pair of permanent magnets may cooperate with a unit ofthe type shown in FIG. 2.

, The embodiment of FIGS. 11*14 is similar to that of FIGS. 2 and 7 inthat it includes an outer tube 35 and inner plug $7 located within andfused to the outer tube .85 at the left end thereof, as viewed in FIGS.11 and 12.

Also, the vibratile element 86 is stretched between the right end of thetube $5 and the right end of the plug 87,

as indicated in FIGS. 11 and 12. However, the damping structure isdifferent from the other embodiments. as

may be seen from FIGS. 11-14, the damping structure in.- cludes an outersubstantially U-shaped strip 88 having a pair of parallel legs extendingalong the inner surface of the tube and having an intermediate portionlocated at the exterior of the tube 85 and surrounded by a coil 92; Nextto the strip 88 is located another substantially U-shaped strip 89 whichengages the inner surface of the strip 38 and is substantiallycoextensive therewith. Both 'of these strips 83 and 89 are made of amagnetic material so tlat they become energized when the coil 92 isenergize A third strip so of substantially U-shaped configuration islocated against the inner surface of the inner strip $9 and has freeends extendingbeyond the same in the interior of the tube 85, these freeends respectively carrying the padding 91. This strip 9t? is made ofnonmagnetic spring material. The strips $S-tl areall made a the exampleillustrated in FIG. 12, and the lower'free ends of the strips 89 and 88with an opposed polarity, so that the free ends of the strips 88 and 89cooperate first to repel each other, and then the free ends of the strip89 attract each other, and the movement of the strip 89 is transmittedto the strip 90 which is moved in this way from the rest position ofFIG. 11 to the damping position of FIG. 12 where the padding 91 engagesthe vibratile element 86 to mechanically prevent the vibration thereof,and in this embodiment also the vibratory element 86 is engaged atopposite faces with equal and opposite forces in order to produce thedamping thereof, so that there is no stretching of the vibratile element86 as a result of the damping thereof.

This embodiment of the invention is of particular ad vantage since itkeeps all of the magnetic fields of the damping structure away from thevibratile element 86 which is charged by the conductors 95 and 96 shownfragmentarily in FIGS. 11 and 12. Thus, with this arrangement themagnetism of the damping means will not interfere with the reproductionof the sound. Furthermore, because a coil 92 is used, when this coil isnot energized there is no magnetism present, as would be the case if apermanent magnet were used, so that for this reason also the structureoperates very reliably to prevent the magnetic forces of the dampingmeans from interfering with the sound producing structure.

If desired the intermediate portions of the strips 88-90 could belocated flush with the left end of the tube 85 or in the interior of theplug 87.

As may be seen from FIGS. 13 and 14, the strip 89 is provided at one ofits free ends with a pair of ears 97 and at its opposite free end with apair of ears 98, and the ears 97 are respectively directed toward theears 98 and the latter also extend toward the cars 97. As a result, whenthe coil 92 is energized the ears 97 and 98 become located relativelyclose to each other, as indicated in FIG. 13, so that the gaptherebetween is quite small and the force of attraction operates veryreliably even if it is not particularly large. Furthermore, as is shownin FIG. 14, the parallel arms of the strip 89 may be provided with anycutouts 99 or the like so as to render these arms more easily bendable.

FIGS. -17 show one of the units of the present invention incorporatedinto a piano structure which includes further features of the presentinvention. Simply by way of example a unit similar to that of FIG. 2 isshown included in the assembly of FIGS. 15-17, although any other unitsdescribed above may be included. Referring now to FIG. 15, which showsthe parts at rest, the structure illustrated therein includes aconventional piano frame 100 and one of the piano keys 101 is shownsupported for turning movement about the rod 102, this illustrationbeing diagrammatic. When the operator actuates the key 101, the latterturns in a clockwise direction about the rod 102. The unit 103, may bethe same as the unit shown in FIG. 2, is provided with a hollow plug104. The unit 103 is attached to the key 101 at its inner end portion bybands 105 and 106. which may be any,

suitable bands such as bands of adhesive tape, for example. When the key101 is in its rest position it rests on a bar 121 made of rubber, forexample. The key 101 additionally carries a pick-up coil 107 which isconnected electrically with an amplifier 108 which is in turn connectedelectrically with a loud speaker 109, so that when the vibratile elementvibrates in the field of the pick-up coil 107 the vibrations will beconverted into a musical sound. The vibratile element 103a of the unit103 is set into vibratory motion by engagement of the key 101, when itis turned to an operating position, with a stop means 110, which is inthe form of a bar of any suitable fairly rigid material which can besound-proofed with respect to the frame 100 in any suitable way, as bylocating any desired padding or the like between the stop means 110 andthe frame 100.

The frame 100 carries a springy a rm 111 which in the position shown inFIG. 15 presses the permanent magnets 112 against a layer of foam rubberor the like 113 carried by an extension 114 of the frame 100. A secondspringy arm 115 is carried by the arm 111, and this springy .free thelatter for vibration.

arm 115 supports at its upper free end a second coil 116 which is woundoppositely to the coil 107 and which is also connected electrically withthe amplifier 108, as illustrated in FIG. 15. This coil 116 cooperateswith the coil 107, in a manner described below, to electrically damp thevibrations of the vibratile element.

An electromagnet 117 is supported on the bottom wall of the frame 100,and this magnet cooperates with an armature 117 carried by the arm 111so that when the electromagnet 117 is energized it will pull the arm 111down into engagement with the layer of foam rubber 118, or the like. Ofcourse, the arms 111 and 115 are made of non-magnetic material.

The structure illustrated in FIG. 15 further includes a pedal 120capable of being turned downwardly by the operators so as to close aswitch 119 located in the circuit of the electromagnet 117 forenergizing the latter when the pedal 120 is actuated.

It will be noted that in the position of the parts shown in FIG. 15, thepermanent magnet 112 cooperate with the magnetic damping arms 10312 ofthe unit 103 to cause the padded ends thereof to be pressed with equaland opposite forces against opposite faces of the vibratile element soas to mechanically prevent any vibrations of the vibratile element. Whenthe key 101 is turned from the rest position of FIG. 15 to operatingposition of FIG. 16, it will strike against the stop means 110, andfurthermore the unit 103 will be moved away from the field of influenceof the magnets 112, so that the springy damping arms move outwardly awayfrom the vibratile element to Upon striking against the stop meansinertia forces induced in the vibratile element set the latter intovibratory motion, and this vibratory motion is picked-up by the pick-upcoil 107 and is converted into a musical sound by the amplifier 108 andthe loud speaker 109. The vibratile element tries to continue to moveafter the key 101 engages the stop 110 and thus vibrates due to inertia.It will be noted from FIG. 16 that the vibratile element is located at arelatively large distance from the coil 116, so that the latter does notenter into the operation at this time. Furthermore, it will be notedfrom FIG. 16 that the coil 116 has moved upwardly from the positionwhich it has in FIG. 15, the springy arm being acted upon in theposition of the parts shown in FIG. 15 so as to be placed in a positionlower than the position which it naturally takes, this latter positionbeing illustrated in FIG. 16. In this way the musical sound is produced.

When the operator releases the key so that it returns from the positionof FIG. 16 back to the position of FIG. 15, it will be seen that theunit 103 will engage the coil 116 just before the key 101 reaches itsrest position, so that just before this rest position is reached thecoils 107 and 116 are located equidistantly from the vibratile element.Therefore, just before the key 101 reaches its rest position the coils107 and 116 cooperate to cancel out any signals which might betransmitted to the amplifier inasmuch as these coils are oppositelywound, and in this way the vibrations are electrically damped. Thus, theelectrical damping takes place just before the mechanical dampingelements have reached a position with respect to the permanent magnets112 which will provide the full force of the mechanical damping. It hasbeen found that the mechanical damping will produce an undesirablehissing sound, and the electrical damping just before the mechanicaldamping reaches its final position eliminates this hissing sound.Actually, the electrical damping by itself would be sufficient to cancelout any sounds when the key returns to its rest position, except that itis frequently desired to repeat the same tone quickly with distinctabrupt periods of silence between repeated tones, and the electricaldamping by itself cannot be relied upon for this purpose. For thispurpose it is essential that the actual vibratory motion of the string 11 be terminated, and this is brought about by the mechanical dampingmeans.

FIG. 17 shows the position in which parts take when the pedal 120 isactuated. As is apparent from FIG. 17, the actuation of the pedal 120will close the switch 119 so as to energize the electromagnet 117 whichdraws the armature 117' down to the position shown in FIG. 17, with theresult that the arm 111 is placed against the layer of foam rubber orthe like 118,.and both the permanent magnet 112 as well as the coil 116are moved downwardly to a position where they no longer influence I theunit 103. Therefore, assuming that the pedal 120 has trically damped,and the, tone will be sustained, and the same is true even if the key isagain actuated before releasing the pedal or if the pedal is releasedafter the key is again actuated so that the parts have the positionshown in FIG. 16. I

In the embodiment of the invention which is illustrated inFIG. 18, thepiano frame 125 carries a rod 127 which pivotally supports the piano key126. This piano key 126 carries a unit 128 which in the illustratedexample is similar to the unit of the invention which is illustrated inFIG. 7.

, In the embodiment of FIG. 18, the vibratile element 128a of the unit128 is energized through a super-sonic generator129, which is connectedwith the line current and which has a well known construction, so as toinduce at the vibratile element a field having a super-sonic frequencywhich is of course inaudible. Thus, when the vibratile element is setinto vibratile motion, this field vibrates with the vibratile element tocause the pick-up coil 130, which is carried by the key 126, to transmitthe vibrations to the amplifier 131 to be reproduced into a musicalsound at the loud speaker 132. This amplifier is connected into one unitwith a detector which detects the super-sonic frequencies and filtersout these frequencies so that only the audible frequencies aretransmitted to the loud speaker 132. Thus, with the embodiment of 'FIG.18, instead of a permanent magnet the super-sonic generator 129 is usedto energize the vibratile element of 126 when the pedal 135 is actuatedby the operator.

The bar 133, which is of an electrically non-conductive material,carries one of the contacts of a switch 138, the other contact of thisswitch 138 beingicarried by'the key .126 and this switch 138 beingclosed in the position of the parts shown in FIG. 18. In addition, theembodiment of FIG. 18 includes a stationary electromagnet 1.36

which is energized by a circuit which includes the switch 138, and thismagnet 136 cooperates with the mechanical damping means 12817 of theunit 1215 to cause the mechanical damping means to' engage the vibratileelement and prevent vibratory motion thereof in the position of theparts shown in FIG. 18.

The bar 133 additionally carries a coil 137 which is wound oppositely tothe coil 131i and which is also connected with the detector andamplifier assembly 131, so that when the parts have the positionshown inFIG. 18

a the vibrations are both electrically and mechanically dampedf Thespring 134 is of such a force that the coil 137 moves upwardly through aslight distance after the key 126 is actuated, so that the electricaldamping takes place just before the key returns to its rest position, as

was described above in connection with the embodiment 7 of FIG. 15.

Of course, when the pedal 135 is actuated, the downward movement of thebar 133 opens the switch 138 so that the electromagnet 136 cannot becomeenergized, and furthermore the coil 137 moves downwardly with the bar133 so that it cannot oppose thecoil 130 and as a result no electricaldamping can take place.' It is therefore apparent that the structure ofFIG. 18 is capable of producing the sameresults as the structure of FIG.15.

In the embodiment of the invention which is illustrated in FIG. 19, thepiano frame 143 carries a rod 142 which pivotally supports the key 141,and when the latter is turned from its rest position to its operatingposition, the portion of the key located forwardly of the rod 142 willturn downwardly. Upon movement of the key 141 to its operating positionit strikes against the stop means 143 in the form of a block of rubberor thelike, and this stop means in this embodiment carries the unit 144which in the particular example illustrated may be the unit which isillustrated in FIG. 2, although any other one of the units of thepresent invention may beused. .The stop means 143 also carries thepick-up coil 145 which is connected electrically through the leads 161with the detector and amplifier assembly 146 which is in turn connectedwith the loud speaker 147. A supersonic generator 148, which may beidentical with the generator 129 of FIG. 18, is connected to the lineand through leads 159 with a primary coil 149 of a transformer, thisprimary coil 149 being carried by the key 141 and being adapted tocoopso as to locate the secondary coil 150 within the primary coil 149when the key 140 is in its rest position which is illustrated in FIG.19.

It will benoted that the support member 151, which is made of anelectrically non-conductive material, has at its left end, as viewed inFIG. 19, an upwardly directed extension located beneath an arm 156 whichis also of an electrically non-conductive material and which at 7 itsright end is provided with a portion extending around the rod 142 sothat the arm 156 can be turned around the rod 142. The key 140 carries apin 166 just beneath the arm 156. Y

The top end of the arm 156 supports theelectromagnet 157 whichcooperates with the mechanical. damping means of the unit 144 in themanner described above when the electromagnet 157 is energized, and aswitch means 153 is provided for energizing the electromagnet 157 whenit has the position shown in FIG. 19. The secondary coil 150 of thetransformer is connected through the leads 160 with the vibratileelement to energize the latter.

When the key 141 is.depressed,the primary-coil 149 moves downwardly to aposition surrounding and over- 14h strikes against the stop means 143,and this vibratory motion is picked-up by thepick-up coil 145 to betransmitted to the discriminator and amplifier assembly 146 whichfilters out of the supersonic frequencies and causes only the audiblefrequencies to be heard'through the loud speaker 147. Whenkey 141engages block 143 the latter is suddenly compressed and produces asudden slight upward movement of unit 144 to cause the'vibratile element13 to vibrate as a result of inertia effects. The filtering out of thesupersonic frequencies with the embodiment of FIG. 19 as Well as withthe embodiment of FIG. 18 prevents distortions in the sound produced bythe loud speaker 147.

When the key 141 is turned to its operating position, the pin 166 turnsthe arm 156 so as 'to raise the electromagnet 157 away from the switchmeans 158 to thus cause the circuit of the electromagnet to becomeinterrupted, and in this Way the electromagnet is de-energized so thatthe mechanical damping means 144b is released and the vibratile elementis free to vibrate before the key strikes against the stop means 143.

In this way a musical sound is provided with the structure of FIG. 19.Upon the release of the key 141 it returns to its rest position so as tocause the electromagnet 157 to become again energized by the switch 158which closes automatically upon the return of the key 141 to its restposition. Of course, the return of the key 141 to its rest positioncauses the primary coil 149 to move upwardly away from the coil 150 soas to prevent cooperation between these coils, and in this way it isimpossible for any vibrations to be electrically transmitted to the loudspeaker. 9

Assuming now that the pedal 154 has been actuated, then the supportmember 151 is in its upper operating position, and at this time even ifthe key 141 returns to its rest position the secondary coil 150 remainswithin the primary coil 149, and the extension 155 of the support member151 prevents the arm 156 from returning to the position thereof shown inFIG. 19, so that there will be no mechanical damping of the vibratileelement, and the tone will be sustained. It istherefore apparent thatthe structure of FIG. 19 also is capable of behaving exactly like aconventional piano.

The embodiment of FIG. 20 is very similar to that of FIG. 19 and thesame elements are indicated with the same reference characters. Thestructure is shown in FIG. 20 in the position which it takes when thekey is in its operating position engaging the stop means 143. The onlydifference between the structure of FIG. 20 and that of FIG. 19 is thatleads 159 connect the supersonic generator 148 to the coil 150, so thatin this embodiment the coil 150 is the primary coil of the transformer,and the secondary coil is carried by the key, this secondary coil beingthe coil 149 with the electrical circuit of FIG. 20. In this embodimentthe secondary coil is connected through leads 160 with the vibratileelement in order to energize the latter. It is apparent that theembodiment of FIG. 20 will operate to produce the desired results also.

The embodiment of FIG. 21 also is very similar to that of FIGS. 19 and20, and the same elements are indicated with the same referencecharacters. The parts are shown in FIG. 21 in the position they'takewhen the pedal is actuated with the key in its rest position. Thestructure of FIG. 21 differs from that of FIGS. 19 and 20 in that thevibratile element itself acts as a pick-up. The leads 162 connect thesupersonic generator 148 to the coil 150 which is still the primarycoil, as is the case with FIG. 20, but leads 165 connect the vibratileelement directly with the detector and amplifier assembly, as shown inFIG. 21. The coil 145 is connected through the leads 164 with thesecondary coil 149 of the embodiment of FIG. 21, so that the field ofhigh-frequency is transmitted from the transformer to the coil 145 sothat this coil 145 sets up the field in which the vibratile elementvibrates, and this vibratile element picks-up its own vibrations andtransmits them to the discriminator and amplifier assembly. It isapparent that the structure of FIG. 21 also will behave in the manner ofa conventional piano.

In the embodiment of the invention which is illustrated in FIG. 22, thepiano frame 171) carries a rod 172 which pivotally supports the key 171,and this key 171 carries the unit 173 which in this embodiment is theunit of the invention which is illustrated in FIGS. 1l-14. When the key171 is actuated by the operator it moves into engagement with a stopmeans 184 in the form of an elongated rubber bar extending along theentire length of the piano so as to cooperate with all of the keysthereof, and in this way inertia forces are induced in the vibratileelement 173a of the unit 173 to set this vibratile element intovibratory motion. With the embodiment of FIG. 22 the key 171 carries acondenser plate 174, and the vibratile element itself forms the otherplate of the condenser, so that the vibratile element and the plate 174cooperate as a variable condenser. The plate 174 and the vibratileelement are connected electrically with a coil 175 carried by the key171, and this coil 175 forms the secondary coil of a transformer whichincludes a primary coil 176 carried by a support member 177 whichincludes a downwardly extending pin 178 of non-circular cross sectionextending through an opening in the frame 170 which is of mating crosssection, so that the support member 177 can only move vertically andcannot turn. A pedal 179 cooperates with the pin 178 so that when thepedal 179 is actuated the support member 177 will be raised. Located inthe path of upward movement of the support member 177 is a switch 180which is opened by upward movement of the support member 177 as isapparent from FIG. 22. This switch 180 is located in an electricalcircuit which is connected with a pair of elongated conductors carriedby the piano frame and cooperating with the contacts of the coil of themechanical damping means of the unit 173, as is apparent from FIG. 22.

A high frequency oscillator 181 is connected to the line and is alsoconnected electrically with the primary coil 176 of the transformer, anda discriminator and amplifier assembly 182 is also connectedelectrically with the oscillator and with the loud speaker 183.

With the construction of FIG. 22, when the key 171 is actuated by theoperator, the secondary coil 175 will move downwardly around the primarycoil 176, so that the high frequency field will be established at thecondenser elements, and their oscillation will be transformed by theamplifier 182 and loud speaker 183 into a musical sound, thediscriminator portion of the assembly 182 discriminating out orfiltering out the super-sonic frequencies which are inaudible, so as toprevent any distortions in the audible frequencies. Of course, when thekey 171 returns to its rest position in FIG. 22, the transformer coilsno longer cooperate with each other so that in this way the electricalcircuit is opened and it is impossible for any of the vibrations of thevibratile element to be electrically transmitted, and of course when thekey 171 returns to its rest position the coil of the mechanical dampingmeans 173b engages the electrically conductive elements 185 so that thiscoil becomes energized and the mechanical damping also takes place.

When the pedal 179 is actuated, the primary coil 176 is moved up intothe secondary coil even if the key 171 is in its rest position, andfurthermore the switch 180 is opened, so that the mechanical dampingmeans cannot become energized, and in this way a tone may be sustained,so that the structure of FIG. 22 also is capable of very closelysimulating the operation of a conventional piano.

In the embodiment of the invention which is illustrated in FIGS. 23-25,the piano frame carries a rod 191 on which the key 192 is pivotallysupported, and this key 192 carries a unit 173 which is identical withthe unit 173 of FIG. 22 and which is shown in detail in FIGS. 11-14. Thekey 192 additionally carries a condenser plate 194 which cooperates withthe vibratile element of the unit 173 in the same way as the condenserplate 174 of the FIG. 22, and electrically conductive bars 185 areprovided to cooperate with the contacts of the coil of the mechanicaldamping means of the unit 173.

In the embodiment of FIGS. 23-25, a second condenser plate 195 islocated at the same distance from the 15 vibratile element as thecondenser plate 194 in the rest position of the parts shown in FIG. 24and this condenser 'plate195 is identical with the condenser plate 194and is itself supported by a springy arm 197 which is connected with theframe 190. An elongated rod 198 or the like is hooked onto the support196 in the manner shown in FIGS. 23-25 and is connected with the pedal199 so when the latter is actuated the rod 198 will be pulleddownwardly.

Connected electrically with the high frequency oscillator, both beforeand after the same, as was the case with the embodiment of FIG. 22, is adiscriminator and amplifier assembly 201 which is connected electricallywith a loud speaker 202.

As was mentioned above, the parts are shown in the rest-position in FIG.24. When the key is actuated the parts move to the position shown inFIG. 23, so that the key 192 comes into engagement with the stop means193 in order to set the vibratile element into vibratory motion.

At this time the vibratile element cooperates with the condenser plate194 to act as a variable condenser, and the supersonic frequencies arefiltered out by the discrimi- 'nator and the sonic frequencies areconverted into a musical sound at the loud speaker.

It will be noted that the frame 190 includes a projection 293 whichcooperates with the upper conductor 185 to prevent the support 1% frommoving upwardly beyond the position thereof shown in FIG. 24. Therefore,when the key is actuated, the support 1% cannot move upwardly andtherefore, as is shown in FIG. 23, the vibratile element is locatedrelatively distant from the condenser plate 195 and the circuit of thecoil of themechanical damping means of the unit 173 is interrupted, sothat the vibratile element is free to vibrate freely in order to producethe musical sound.

Upon return of the key from the operating position of FIG. 23 to therest position'of FIG. 24, the condenser plate 195 will become located atthe same distance from the vibratile elementas the condenser plate 194,and in 'this position of the parts the two condenser plates oppose eachother so as to cancel out any signals which might be provided byvibration of the vibratile element, and in A this way electrical dampingtakes place with this embodiment.

Also, when the contacts of the coil of the mechanical damping meansengage the conductors 185, the mechanical damping means is also actuatedin order to mechanically damp thevibrations, and the electrical dampingprevents the transmission of any hissing sounds, as was pointed outabove.

When the pedal of the embodiment of FIGS. 23-25 is actuated, the partstake the position which is illustrated in FIG. 25. Thus, the support 196is lowered against the 'force of the spring 197, and as a result theconductors 185 are moved away from the coil of the mechanical dampingmeans, so that the mechanical damping can no longer take place. Also,the lower condenser plate 195 'is moved away from the vibratile element,so that there Thus, with this embodiment of the invention it isnecessary to provide only a pair of arms 196 at the opposite ends of thepiano, and a single elongated strip 195 can be supported at its oppositeends by these arms to cooperate with all of the keys, whiletheconductors 185 can also extend along the entire length of the piano andbe supported at their ends by the arms 196 in order to cooperate withall of the coils of all of the units 173, so that when the entire pianostructure is considered the embodiment of FIGS. 23-25is quite simple.

The units 260 and 201 are of a well known construction. The highfrequency oscillator. 2% has its oscillator tank circuit connected withone lead to the condenser plates and with its other lead to thevibratile element.

I Also, although the unit 260 is called a high frequency oscillator, inthe case of FIGS. 23-25 as well as in the case of 131 of FIG. 22, theoscillator can operate at radio frequencies as well as at frequencieshigher'than radio frequencies. Y

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofpianos diifering from the types described above.

While the invention has been illustrated and described as embodied inelectric pianos, it is not intended to'be limited to the details shown,since various modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

Without further analysis, theforegoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. For use in a musical instrument, in combination, a elongated tubularhousing having a hollow interior portion; a string carried-by saidhousing and having a magnetic stretched portion located in said interiorportion of said housing spaced from the walls thereof; and a screwmemberthreadedly carried by said housing and cooperating with said string forstretching said portion thereof to a predetermined degree, said screwmember being also a magnet for magnetically influencing the stretchedportion of said string.

2. In a musical instrument, in combination, a vibratile member adaptedto be set into vibration for participating in the production of amusical sound; support means supporting said vibratile member for freevibratory motion along at least a portion of said vibratile member, saidportion of said vibratile member when it is'unengaged by any otherelement assuming a predetermined position when said vibratile member isat rest; and'damping means cooperating with said vibratile member fordamping the vibratory motion thereof without moving said portion ofbratile member with equal and opposite forces for damping the vibrationsof said vibratile member without plac ing said vibratile member in anyposition other than that which it would naturally assume when at restand uninfiuenced by any other elements; and means cooperating with saiddamping members for movingthe same away from said vibratile member tofree the same for vibratile motion and back into engagement with saidvibratile member to damp the vibrations thereof.

4. In a musical instrument, in combination, a vibratile member having anelongated portion adapted to be.

set into vibratory motion to participate in the produc tion of musicalsound; support means supporting said vibratile member for free vibratorymotion at said portion thereof; a pair of damping members locatedsubtile member having an elongated portion adapted to. be set intovibratory motion for participating in the pro duction of a musicalsound; ,a pair of elongated springy arms respectively located atopposite sides of and ex-' tendingvsubstantially parallel to saidvibratile member, said arms being substantially equidistant from saidvibratile member and having free damping end portions respectivelydirected toward opposed faces of said portion of said vibratile member;the resiliency of said arms maintaining said free damping end portionsthereof out of engagement with said vibratile member so that the latteris free to vibrate at said portion thereof; and magnetic meanscooperating with said arms for moving said free damping end portionsthereof with equal and opposite forces into engagement with said opposedfaces o f'said vibratile member, respectively, to damp the vibrationthereof without exerting any distorting forces on said vibratile member.t

6. In a musical instrument, in combination, an elongated vibratilemember having an elongated portion adapted to be set into vibratorymotion for participiating in the production of a musical sound; supportmeans suporting said vibratile member for free vibratory motion at saidportion thereof; a first pair of magnetic parallel strips located nextto each other on one side of said vibratile member in spaced relationthereto and extending substantially parallel thereto, said first pair ofstrips including an inner strip and an outer strip with said inner striplocated between said outer strip and said' vibratile member; a. secondpair of elongated magnetic strips located next to each other on theopposite side of said vibratile member from said first pair of stripsand being spaced from said vibratile member by substantially the samedistance as said first pair of strips and also extending parallelthereto, said second pair of strips also including inner and outerstrips with the inner strip located between said outer strip and saidvibratile member, said support means cooperating with the outer stripsof said first and second pair of strips for preventing movement of saidouter strips away from said vibratile member; and magnetic,meanscooperating with said first and second pair of strips for'inducing one polarity in said first pair of strips and an oppositepolarity in said second pair of strips, whereby said first pai'r ofstrips will repel each other and said second pair of strips will repeleach other to cause the inner strips to approach each other, and saidinner strips approaching each other to an extent where they becomeattracted to each other due to their opposite polarity; and dampingmeans co-t operating with said inner strips to move into engagement withsaidvibratile member for damping the vibratory motion thereof when saidinner strips are attracted toward each other. I

7. For use in a musical instrument, in combination, an elongated tubularhousing; an elongated vibratile member having an elongated portionlocated in the interior of said housing spaced from the walls thereofand adapted to, be set into vibration for participating in theproduction of a musical sound; and magnetic damping means carried bysaid housing and having a portion locat'ed in the interior thereof forcooperating with said portion of said vibratile member for damping thevibration thereof.

8. In a musical instrument, in combination, an elongated tube; avibratile member carried-by said tube and having an elongated portionlocated in' the interior of said tube spaced from-the walls thereof tobe set into free vibratory motion for participating in the production ofa musical sound; damping means located in said tube for cooperating withsaid portion of said vibratile morn-s ber for damping the vibratorymotion thereof; and means located at the exterior of said tube andcooperating with;

said damping means for actuating the same.

9. A process for manufacturinga unit for use in a musical instrument,comprising the steps of fixing a string to one end of an elongatedhollow tube; locating in said tube a plug for axial movement therein'andconnectingthe string also to said plug; axially moving said plug andtube with respect to each other. until the string is tensioned to apredetermined degree; and then" fixing said plug to said tube tomaintain said string stretched to said predetermined degree.

10. A process for manufacturing a unit for use in a musical instrument,comprising the steps of placing a plug in an elongated hollow tubularmember for axial movement therein; connecting a string to said plug andto said tubular member so that said string will become stretched duringaxial movement of said-plug and tubu-v lar member one with respect totheother; locating between said plug and tubular member a damping meanshaving a portion directedtowards part of the string bea tween said plugand tubular member for damping the string; axially moving'said plug andtubular member tubular member and string, so that said dampingmeans alsoforms part of said unit.

11. A unit for use in a musical instrument, comprising,

in combination, an elongated hollow tube of non-magnetic material havinga closed end and an opposite open end; a plug located in said open endof said tube and closing said open end, said plug also being made of anon-mag netic material; a'string fixed to said'clos'ed end of said tubeand said plug and stretched between said closed end of said tube andsaidplug, said string being adapted to vibrate to participate in theproduction of a musical sound; a pair of elongated strips of magneticmaterial respectively located at opposite sides of said string andextending sub-v stantially parallel thereto, said strips being fixedbetween said plug and tube and each strip being folded upon itself andhaving a pairof portionslocated next to each other, said strips being ofa springy material and remaining by their own resiliency distant fromsaid string next'to the 7 wall of said tube in the interior thereof, theportions of;

said strips which are nearest to said string having free ends adapted tomove toward said string to damp the vibrations thereof, whereby when onepolarity is'induced in one of said strips and an opposite polarity isinduced in the other of said strips the portions of each strip willrepel each other so that the strip portions nearest to said string willmove toward each other and will then attract each other due to theiropposite polarity so as to move with equal and opposte forces towardsaid string to damp the vibration thereof without stretching said stringout of; the position which it naturally-takes due-to-thetension of thestring between said closed end ofsaid tube and said 7 plugs.

12. For use in a musical instrument, in combination; an elongatedvibratile member adapted to be set into 1i). netic material andrespectively having free damping end portions movable toward and awayfrom said vibratile member for engaging the latter to damp the vibratorymotion'thereof; and magnetic means cooperating with said vibratilemember and said springy members for inducing one polarity in saidspringy members and an opposite polarity in said vibratile member sothat said springy members are attracted to said vibratile member at saidfree damping end portions of said springy members for engaging saidvibratile member at opposed surfaces thereof with equal and oppositeforces to damp the vibration of said vibratile member.

13. In a musical instrument, in combination, an outer magneticsubstantially u-shaped strip having a pair of parallel legs and anintermediate portion between said legs at oneend of said legs, said legshaving free ends distant from said intermediate portion; an innermagnetic strip of substantially U-shaped configuration located along andengaging said outer strip at said intermediate portion and legs thereof,said inner strip having free ends located next to the free ends of saidouter strip and said inner strip' being made of a springy material sothat said free ends of said inner strip are movable toward and away fromeach other; means cooperating with said outer strip for preventing saidfree ends thereof from moving away from each other; an electricallyconductive coil surrounding the intermediate portions of said U-shapedstrips for inducing at the freeend portions of said strips, when saidcoil is energized, a given polarity at the adjoining free end portionsat one side of an axis extending between said legs-and an oppositepolarity at the free end portions at the opposite side of said axis, sothat the free end portions of said strips at each side of said axis willrepel each other until the free end portions of said inner stripapproach each other sufficiently to be attracted toward each other bytheir opposed polarity; an elongated vibratile member extending parallelto said axis; and damping means located on opposite sides of saidvibratile member and operatively engaged by said free end portions ofsaid inner strip to be moved thereby with equal and opposite forces intoengagement with opposed parts of said vibratile member for engagingthelatt'er to damp vibrations I thereof when said coil is energized.

next to the free ends of said outer strip andssaid inner strip beingmade of a spring'y material so that said free 1 ends of said inner stripare movable toward and away from each other; means cooperating with saidouter strip for preventing said free ends thereof from moving away' fromeach other; an electrically conductive coil surrounding the intermediateportions of said U-shaped strips for inducing at the free end portionsof said strips,

when said coil is energized, a given polarity at the adjoining free endportions at one side ofan axis extending between said legs and anopposite, polarity at the free end portions at the opposite side of saidaxis, so that the free end portions of said strips ateach side of saidaxis will repel each other until the free endportions of said innerstrip approach eachiother sufliciently to be attracted toward each otherby their opposed polarity; an

elongated vibratile member. extending parallel to said axis, said freeend portions of said inner strip each being provided with a pair oflateral flap portions and the lateral 'flap portions at each free endportion of said inner strip extending toward the lateral flap portions.at the other free end portion of said inner strip, so that saidlateral'flap portions are located relatively near to each other whensaid free end portions of said inner strip attract each other; anddamping means located on opposite sidesof said vibratile member andoperatively engaged bysaid free end portions of said inner strip to bemoved thereby withequal and opposite forces into engagement with opposedparts of said vibratile member for engaging the latter to dampvibrations thereof when said coil is enerlegs at one end of said legs,said legs having free ends distant from said intermediate portion; aninner magnetic strip of substantially U-shaped configuration locatedalong and engaging said outer strip at said intermediate portion andlegs thereof, said inner strip having free ends located next to the freeends of said outer strip and said inner strip being made of a springymaterial so that said free ends of said inner strip are movable towardand away from each other; means cooperating with said outer strip forpreventing said free'ends thereof from moving away from each other; anelectrically conductive coil surrounding the intermediate portions ofsaid U-shaped strips for inducing at the free end portions of saidstrips, when said coil is energized, a given polarity at the adjoiningfree end portions at one side of an axis extending between said legs andan opposite polarity at the free end portions at the opposite side ofsaid axis, so that the free end portions of said strips at each sideofsaid axis will repel each other untilthe free end portions of saidinner strip approach each other sufiiciently to beattracted toward eachother by their opposed polarity; an elongated vibratile member extendingparallel to said axis, the legs of said inner strip being formed withcutouts so that said legs are easily bendable; and damping means locatedon opposite sides of said vibratile member and operatively engaged bysaid free end portions of said inner strip to be moved thereby withequal and opposite forces into engagement with opposed parts of saidvibratile member for engaging the latter to clamp vibrations thereofwhen said coil is energized.

16. In a piano, in combination, a piano key turnable from a rest to anoperating position; an elongated vibratile member carried by said keyfor turning movement therewith and adapted to have a portion thereof setinto vibratory motion for participating electrically in the productionof a musical sound; stop means located in the path of movement of saidpiano key for setting said por tion of said vibratile member intovibratory motion; a pick-up coil carried by said key adjacent saidvibratile member for picking up the vibration thereof; a damping coilconnected in electrical opposition with said pick-up coil and located atthe same distance from said vibratile member as said pick-up coil whensaid key is in the region of said rest position thereof so that saidcoils oppose each other electrically for cancelling out the transmissionof vibratory movement of said vibratile member when from a rest to anoperating position; an elongated vibratile member carried by said keyfor turning movement therewith and adapted to have a portion thereof setinto vibratory motion for participating electrically in the productionof a musical sound; stop means located in the path of movement of saidpianokey for setting said portion of said vibratile member intovibratory motion; a pick-up coil carried by said key adjacent saidvibratile member forpicking up the vibration thereof; a damping coilconnected in electrical opposition with said pick-up coil and located atthe same distance from said vibratile member as said pick-up coil whensaid key is in the region of said rest position thereof so that saidcoils oppose each other electrically for cancelling out the transmissionof vibratory movement of said vibratile memberwhen said key is in theregion of its rest position; support means supporting'said damping coilfor movement away 21 7 g from said vibratile member when said key is insaid rest position thereof; electro-magnetic means cooperating with saidsupport means for moving said damping coil away from said vibratilemember when said electro-magnetic means is energized; and pedal-operatedmeans cooperating with said electro-magnetic means for energizing thesame, so that when the operator actuates said pedal-operated means thedamping coil will be moved to a position Where it is incapable ofopposing said pick-up coil and the sound produced by the vibratorymotion of said portion of saidvibratile member will be sustained. I

- 18'. In a musical instrument, in combination, a pair. of partscooperating electrically to participate in the production of a musicalsound, said pair of parts being formed respectively by an elongatedvibratile member having a portion adapted to be setinto vibratory motionand a pick-up coil located adjacent said portion of said vibratilemember; means cooperating electricallywith one of said parts forgenerating at said one part a field having a super-sonic frequency; andmeans cooperating with the other said parts for amplifying signalsproduced by the vibrations of said portion of said vibratile member andfor filtering out the super-sonic inaudible frequencies.

19. In a piano, in combination, a piano key movable from a rest positionto an operating position and back to said rest position; an elongatedvibratile member carried by said key for movement therewith andsupported on said key for free vibratory movement at a portion of saidvibratile member; means cooperating electrically with said vibratilemember for generating at said vibratile member a field having asuper-sonic frequency; a pick-up. coil carried by said key for movementtherewith and located adjacent said vibratile member for picking upthe'vibrations thereof; a second, damping coil located adjacent saidvibratile member at the same distance therefrom as said pick-up coilwhen said key is in said rest position thereof for cancelling outvibrations of said vibratile member when said key is in the'restposition thereof, said damping coil being connected in electricalopposition with said pick-up coil; support means support ing saiddamping coil for movement away from said vibratile member when said keyis in said rest position thereof; pedal means capable of being actuatedby the operator and cooperating with said support means for moving saiddamping coilaway from said vibratile member; electrical meanscooperating with said coils for amplifying the signals received therebyand for filtering out super-sonic frequencies; magnetic damping meanscooperating with'said vibratile member for mechanically damping, thevibrations thereof; a stationary electro-magnet cooperating with saidmagnetic damping means for actuating the same to mechanically damp saidvibratile member when said key is in said rest position thereof; andswitch means located in the circuit of said electro-magnetic means andoperatively connected with said support means for automatically openingthe latter circuit when said pedal means is actuated to move saiddamping coil away from said vibratile member when said key is in saidrest position thereof, so that said vibratile member will not bemechanically damped when said pedal is actuated. I

20. In a piano, in combination, a pairof parts'which cooperateselectrically to participate in the production of a musical sound, saidparts respectively being an elongated vibratile member and a pick-upcoil; key means cooperating with said vibratile member for setting thesame into vibratory motion when said key means is actuated by theoperator; a pair of transformer coils one of which is carried by saidkey means for movement therewith and the other of which becomes locatedwithin said one coil when said key means is actuated, one of said coilsbeing a primary coil and the other of said coils being a secondary coil;means cooperating with said primary coil for energizing the same at asuper-sonic frequency;

means connecting said secondary coil electrically with one of said partsfor inducing at the latter a field of said super-sonic frequency whensaid key means is actuated; and means cooperating with the other of saidparts for amplifying signals picked up by said other part and forfiltering out the super-sonic frequencies, said transformer coilsvbeingaxially displaced from each other and out of overlapping relation withrespect to each other when said key means is in its rest position toprevent the transmission of signals which would transform vibrations ofsaid vibratile member into a musical sound, so that said transformercoils also cooperate to prevent the operation when said key means is insaid rest position thereof.

21. In a piano, in combination, a pair of parts which cooperateselectrically to participate in the production of a musical sound, saidparts respectively being an elongated vibratile member and a pick-upcoil; key means cooperating With said vibratile member forsetting thesame into vibratory motion when said key means is actuated by theoperator; a pair of transformer coils one of which is carried by saidkey means for movement therewith and the other of which becomes locatedwithin said one coil when said key means is actuated, one of said coils.being a primary coil and the other of said coils being a secondarycoil; means cooperating with said .primary coil for energizing the sameat a super-sonic frequency; means connecting said secondary coilelectrically with one of said parts for inducing at the latter a fieldof said super-sonic frequency when said key means is actuated; meanscooperating with the other of said parts for amplifying signals pickedup by said other part and for filtering out the super-sonic frequencies,said transformer coils being axially displaced from each other and outof overlapping relation with respect to each other when said key meansis in its rest position to prevent the transmission of signals whichwould transform vibrations of said vibratile member into a musicalsound, so that said transformer coils also cooperate to prevent theoperation when said key means is in said rest position thereof; andpedaloperated means cooperating with the transformer coil which is notcarried by said key means for moving the latter coil into thetransformer coil which is carried by said key means when said key meansis in said rest position thereof for sustaining a tone produced byvibratory motion of said vibratile member.

22. In a piano, in combination, a key pivotally supported for turningmovement from a rest to an operating position and having a forwardportion which moves downwardly during movement of said key from saidrest to said operating position thereof; avprimary transformer coilcarried by said forward portion of said key for movement therewith;means cooperating with said coil for energizing the latter at asuper-sonic frequency; a support member mounted for vertical movement; asecondary coil carried by said support member substantially coaxiallywith said-primary coil beneath the latter when said key is in said restposition thereof, said primary coil moving to a position surrounding andoverlapping said secondary coil When said key is moved from said rest tosaid operating position; stop means located in the path of movement ofsaid key during movement of the latter from said rest to said operatingposition for stopping the movement of said key; a vibratile elementcarried by said stop means to be set into vibratory motion by inertiawhen said stop means is engaged by "said key; means connecting saidvibratile elementelectrically with said secondary coil to charge saidvibratile element with said super-sonic frequency; mechanical clampingmeans responsive to electromagnetic forces and cooperating with saidvibratile element for mechanically damping the vibratory movementthereof; an electro-magnet cooperating with said mechanical dampingmeans for actuating the same to damp said vibratile element when saidkey is in said rest position thereof; motion transmitting meanscooperating with said key and with said electro-magnetic means formovingthe latter away from said mechanical damping means to deactivate saidmechanical damping means when said key is moved from said rest to saidoperating position; a pick-up coil carried by said stop means adjacentto said vibratile element for picking up the vibrations thereof;electrical means cooperating with said pick-up coil for amplifying thesignals received by said pick-up coil from said vibratile element andfor filtering out the super-sonic frequencies; and pedal operated meanscooperating with said'support member for raising'the same when saidpedal operated means is actuated by the operator, so that upon operationof said pedal operated means said secondary coil moves into said primarycoil even when said key is in saidrest position thereof, said supportmember also moving said'electro-magnetic means away from saidmechanicoil of a transformer carried by said forward portion of said keyfor'movement therewith; a support member a mounted for verticalmovement; a primary transformer coil carried by said support membersubstantially coaXially with said secoondary coil and located beneaththe latter when said key is in said rest position thereof, saidsecondarycoil moving downwardly to a position surrounding andoverlapping said primary coil when said key is moved to said operatingposition thereof. means coopcrating with said'primary coil forgenerating at the latter a field having a super-sonic frequency; stopmeans cooperating with said key for stopping the movement thereof whensaid key is in said operating position; an'elonga-ted vibratile elementcarried by said stop means to be set into vibratory motion by inertiaupon engagement bysaid stop means with said key when the latter is movedto said operating position; means connecting said secondary coil withsaid vibratile element for'inducing in the latter a field of saidsuper-sonic frequency; a pick-up'coil carried by said stop meansadjacent to said vibratile. element for picking up the signals producedby the vibratory motion of said vibratile element; means cooperatingwith said pick-up coil for amplifying the audible vibrations and forfiltering out the inaudible super-sonic vibrations; mechanical dampingmeans cooperating with said vibratile element for damping the vibrationthereof, said mechanical damping means being responsive toelectro-magnetic forces; electro-rnagnetic means cooperating with saiddamping means, for actuating the same to mechanically damp the vibratorymotion of said vibratile element; mo-

tion transmitting means operatively connected with said key and withsaid e'lectro-magnetic means moving the; I same away from saidmechanical damping means to, prevent the later from damping saidvibratile element when said key is moved from said rest to saidoperating position, said motion transmitting means being located in the1 path of movement of said support member during upported for turningmovement from a rest to an operating position, said key having a forwardportion which moves 7 downwardly during movement of said key from saidrest to said operating position thereof; a secondary transformercoilcarried by said forward portion of said key for downward movementtherewith; a support, member guided for vertical movement; a primarytransformer coil carried by said support member substantially coaxially1 With said secondary coil at a position located beneath the latter whensaid key isin said rest position thereof; means cooperating with saidprimary coil for generating at the latter a field having a super-sonicfrequency; stop means located in the path of movement of said key to been gaged and suddenly moved by the latter when said key is moved to saidoperating position thereof; an elongated vibratile element carried bysaid stop means to be set into vibratory motion by inertia uponengagement of said stop means with said key when the latter is moved tosaid operating position; a pick-up coilcarried by-said stop means forpicking up the vibrations'of said vibratile element;,means connectingsaid secondary "transformer coil electrically with'said pick-up coilforinducingthe latter a field of said super-sonicfrequency,"so, that said.field is influenced by the vibrations of said vibratile ele-'- ment;means cooperating with said vibratile elementfor amplifying the signalsproduced by vibration thereof and for filtering out super-sonicfrequencies, so that only audible frequencies are amplified; mechanicaldamping means cooperating with said vibratile element for mechanicallydamping the vibration thereof; electromagnetic means cooperating withsaid mechanical damping means for actuating the latter to dampthevibrations of said vibratile element; motion transmitting meanscooperating with said key and with said electro-magnetic means formoving the same away from said mechanical damping means so that thelatter does not damp the vibrations of said vibratile element when saidkey is moved from said rest to said operatingv position thereof; andpedal operated means cooperating with said support member for raisingthe latter when said pedaloperated means is actuated by'the operator, tomove said primary coil into said secondary coil even when said key is ata rest position thereof, said'support member when it is raised alsocooperating with said electro-ma gnetic means for mov-i ing the sameaway from said mechanical damping means, so that upon actuation of saidpedal operated means a tone produced by vibration of said vibratileelement will be sustained.

25. In a piano, in combination, a key turnably sup ported for turningmovement between a rest and anop crating position; stop meanscooperating with said key to be engaged by the latter when said key ismoved to said operating position; an elongated vibratile element carriedby 'said key to be set into vibratory motion by inertia upon engagementbetween sai dkep and stop means; a condenser plate carried by said keyadjacent said vibratile element to cooperate with the latter as a vari26. In a piano, in combination, a key turnably sup ported for turningmovement between a rest and an operating position; stop meanscooperating with said key .to be engaged by the latter when said key ismoved to said operating position; an elongated vibratile element carriedby said key to be set into vibratory motion'by inertia upon engagementbetween said key and stop means; a condenser plate carried by said keyadjacent said vibratile element to cooperate with the latter as avariable condenser during the vibration of said vibratile element; andan electrical circuit cooperating with said vibratile element and saidcondenser plate, said circuit including a high frequency oscillatorcooperating with said plate and. I

1. FOR USE IN A MUSICAL INSTRUMENT, IN COMBINATION, AN ELONGATED TUBULARHOUSING HAVING A HOLLOW INTERIOR PORTION; A STRING CARRIED BY SAIDHOUSING AND HAVING A MAGNETIC STRETCHED PORTION LOCATED IN SAID INTERIORPORTION OF SAID HOUSING SPACED FROM THE WALLS THEREOF; AND A SCREWMEMBER THREADEDLY CARRIED BY SAID HOUSING AND COOPERAT-